If it is a partially trusted click once application it wont be visible
in the task manager. But you will see a process called Applaunch.exe,
which acts as a shim for the click once application.

You can read more about this here

http://blogs.msdn.com/shawnfa/archive/2005/11/30/498610.aspx

Depending on how where you're executing your unrestricted permission demand,
you may not actually be testing whether your application is fully trusted.
When Demand is called for a standard CAS permission, the stack frame in
which the method is called is not evaluated for the demanded permission.
(i.e.: The method from which you call Demand gets skipped over.)  If you're
making the demand from your application's Main method, there won't be any
stack frame evaluated from your application's assembly, and the demand will
pass even if your assembly is not granted unrestricted permissions.  To
ensure that at least one method from your assembly is included in the
demand, simply move the Demand call into another method that can be called
from your Main method.  e.g.:

Sub Main()

     DemandFullTrust()
     '...

End Sub

Private Sub DemandFullTrust()

     Dim p As New
System.Security.PermissionSet(Security.Permissions.PermissionState.Unrestricted)
     p.Demand()

End Sub